Swab and Water dog

Swab noun - One who operates or navigates a seagoing vessel.

Water dog and swab are semantically related In some cases you can use "Water dog" instead a noun "Swab".

Water dog noun - A dog accustomed to water and usually trained to retrieve waterfowl.

Swab and water dog are semantically related in sailor topic. Sometimes you can use "Swab" instead a noun phrase "Water dog", if it concerns topics such as person who travels by sea.